Moistening means for duplicating apparatus



1951 H. P. KElL 2,572,158

MOISTENING MEANS FOR DUPLICATING APPARATUS Filed July 12, 1947 4 Sheets-Sheet l INVENTOR. Henry R Kei/ g/r -e/ M13144;

Afforney Oct. 23, 1951 H; P. KElL 2,572,158

MOISTENING MEANS FOR DUPLICATING APPARATUS Filed July 12,. 1947 4 Sheets-Sheet 2 FIG. 2.

IN VEN TOR. Henry P. Ke/l A Home y Oct. 23, 1951 P, KElL 2,572,158

MOISTENING MEANS FOR DUPLICATING APPARATUS A Home y H. P. KEIL MOISTENING MEANS FOR DUPLICATING APPARATUS Filed July 12, 1947 Oct. 23, 1951 4 Sheets-Sheet 4 IN VEN TOR. Henry P. Ke/l MW/Q6 44 Afforney Patented Oct. 23, 1951 MOISTENING MEANS FOR DUPLICATING APPARATUS Henry P. Keil, Chicago, Ill., assignor to The Fixture Hardware Corporation, Chicago, 111., a corporation of Illinois Application July 12, 1947,v Serial No. 760,537

1 Claim.

1 My invention relates to duplicating apparatus of the type wherein a master sheet having the material to be copied printed thereon in mirror script, is contacted by a copy sheet havinga solvent for the printing ink used, in order to take off copies of the material on the master sheet.-

In machines of this character great difficulty has been encountered in obtaining uniform distribution of the solvent fluid on the copy sheet. The solvent fiuid employed must of necessity be quite volatile in order for the copy sheets to dry quickly once the transfer of material from the master sheet to the copy sheet has been accomplished. Such a fluid if left exposed, of course, evaporates quickly. Moreover, vapors of such fluid are a hazard, particularly if they happen to be of an inflammable nature.

Bearing in mind these difiiculties encountered with moistening apparatus in existing machines of this character, it is the purpose of my invention to provide a novel moistening means for applying moisture to a copy sheet in a duplicating machine of the character described, wherein uniform distribution of the moisture over the moistening rollers is obtained in a new and useful manner.

It is also a purpose of my invention to provide a roller moistener of the character described, wherein the moistening liquid is applied to a roller by being delivered through openings in a tube mounted adjacent to the roller in such proximity thereto that the attraction of the fluid for the surface of the tube and the adjacent roller will overcome the surface tension of the fluid, and cause the liquid to how along the tube between the adjacent openings a substantial distance, and thus provide uniform distribution lengthwise of the roller from the tube in close proximity to, but not in contact with the roller surface.

According to a preferred embodiment of my invention, I utilize a pumping system to deliver liquid to a tube and the liquid is allowed to flow along the tube and out through five or six spaced openings lengthwise of the tube. Any excess of liquid that may be delivered to the roller from the tube is allowed to fall into a drain trough and return to a covered tank in the machine. No pressure of liquid is provided in the tube since spraying of the liquid is distinctly to be avoided for the reason that it causes uneven moistening, and furthermore it provides additional opportunity for vaporization of the fluid.

The nature and advantages of my invention will appear more fully from the following de-v scription and the accompanying drawings wherein a preferred form of the invention is shown. It should be understood, however, that the drawings and description are illustrative only and should not be taken as limiting the invention except insofar as it is limited by the claim.

2 In the drawings: Figure 1 is a view in side elevation of a duplicating machine embodying my invention;

Figure 2 is a plan view of the machine;

Figure 3 is a. sectional view taken substantially midway through the machine on a longitudinal line;

Figure 4 is an enlarged fragmentary sectional view through the moistening roller to which moisture is first applied, and the associated moistening tube;

Figure 5 is a sectional view taken on the line 51-5 of Figure 3; and

Figure 6 is a sectional view taken on the line 6-45 of Figure 5.

Referring now to the drawings, my invention is shown as applied to a duplicating machine of the type wherein a master sheet is applied to a drum H), and copy sheets are fed from a copy sheet feed tray H through a moistening mechanism to be pressed against the master sheet on the drum it. I employ the usual mechanical feeding device 2 for feeding sheets to a pair of feeding and moistening rollers l3 and I4, where. the copy sheets are moistened on one surface and advanced to the meeting line of the drum Iii and the, platen roller for pressing the copy sheets against the drum.

The moistening roller mechanism includes a transfer roller 46 which contacts the roller 4. and an initial supply roller ii to which the moistening fluid is first distributed. This supply roller is mounted over a drain trough i8 that is'pro vided with a lip at ii) that cooperates with the forward edge, 28 of the feeding tray II to guide, the moistened copy sheets to the rollers l3 and. I l. The machine has suitable drive means inch-- cated at 25, 22, 23, and 24, for driving the moistenin rollers and the sheet feeding device 12 from the drum. This driving mechanism is shown in my prior application, Serial No. 726,502, filed February 5, 1946, for Duplicating Apparatus, and since it forms no part of the present in vention, will not be further described.

The machine in which the drum i mounted has two side frames 25 and 26 provided withsuit-. able bearings, for the drum shaft 2?. On the inside of the side frame 25 I mounta gear 28 and connect it through the side frame to an operating handle 29. The gear 28 drives a gear 30 on the drum shaft 21 and the gear 36 in turn drives a gear 3! which drives. a pinion 32 that is fixed to a sprocket wheel 33. A chain 34 is driven by the sprocket wheel 33, and drives a sprocket wheel 35 on a. stub shaft 36 that is mounted in the side frame 25. The sprocket wheel 35 has a bell crank '37 thereon provided with a pin 38 engaging a coupling member 39 on a shaft Mi.

A liquid tank 4| is supported on a cross rod 42 between the side frames 25 and 26, and, has

;;suitablebearings as indicated at 43 for the shaft 40. On the'other end of the shaft 40 a crank arm 44 is mounted, and this arm is fastened to a piston 45 of a. pump 46. The pump 46 is pivotally mounted by a pin 41 upon a bracket 48 that is mounted in the tank and forms part of the support for the bearing 43. Inlet means 49 and an outlet tube 50 are provided for the pump 46.

The tube 50 has a flexible conduit secured thereto, and this flexible conduit extends upwardly where it is fitted over one end of a moistening tube 52. The moistening tube 52 is mounted in one end piece 53 of a sub-frame that carries the moistening rollers l3, |4, |6 and IT. The other end piece 54 of the sub-frame serves to mount a part of the driving mechanism consisting of the members 23 and 24. The tube 52 has a small inlet opening 55 of substantially less diameter than the conduit 5| so that in pumping liquid up through the conduit 5| there will be a build up of pressure in the conduit and a lessening of pressure as the pump operates but a fairly steady flow of liquid into the tube 52 because of the restriction at 55.

The tube extends across the sub-frame between the side pieces 53 and 54, and is firmly secured in both side pieces to lie closely adjacent to the downwardly moving surface of the roller l1. Figure 4 of the drawings shows the relative positions of the roller l1 and the tube 52. However the spacing between the tube and the roller is a critical matter, according to my invention, and is exaggerated somewhat in Figure 4. Preferably the tube is placed within about ten to fifteen thousandths of an inch from the roller. Several openings 55 are provided in the tube on the side facing the roller, so that the liquid may trickle out of the openings as it is supplied to the tube through the inlet 55, and flow downward alongside the tube to the narrow space between the tube and roller. By spacing the tube cor rectly from the roller, I find that the liquid will spread across the gap between the tube and the roller and owing to its attraction for the surfaces of the tube and the roller it will run lengthwise of the tube very quickly between the openings 56 even though the roller is being rotated all the time. I attribute this action to the fact that the narrow gap is of substantially capillary proportions so that the surface tension of the liquid is not sufficient to prevent its spreading to both the tube surface and the roller surface across the gap between them. Whatever the explanation may be theoretically I find that practically the liquid spreads very quickly along the tube so that a uniform distribution of liquid from end to end of the tube is obtained on the roller. This is true even though the roller and tube are not level and considerably more liquid is fed through v the openings at one end of the tube than is fed through the openings at the other end.

Uniform moistening of the roller l! in this fashion assures transfer of uniform distribution of moisture to the transfer roller I5 and from there to the roller M. The roller l6 must of necessity be somewhat porous or absorbent since it carries a reserve of liquid once it becomes moistened by contact with the roller H. The degree of transfer of liquid to the roller 4 is suitably controlled by the nature of the roller i6 and the pressure of the rollers against each other. If there is any excess liquid on the roller I? it flows down and falls oif into the tank l8 where it is drained through an outlet 51 and a conduit 58 into" thetank 4|.

4 f Figure 3 illustrates the means provided for filling the tank 4| with a fresh supply of liquid. This means comprises a pipe 59 and a filling head 69. The filling head is mounted on a cross rod 6| between the side frames and 26, and is closed by a cap 52.

It will be observed that as shown by the drawings, the entire tank 4| is closed except for the conduits 5| and 58, and the inlet pipe 59. Liquid evaporation from the tank is thus prevented except as it may evaporate through the conduits 5| and 58 which are open at the top. All excess liquid that may be recovered from the roller 17 is immediately drained back into the tank. It is therefore only during the operation of the machine and for a short time thereafter that any substantial surface of liquid is exposed for evaporation. The roller I1 is a synthetic rubber roller having a smooth surface so that it dries quite rapidly. The roller l6 being somewhat porous or absorbent takes considerable time to dry out, but it does not carry any substantial quantity of liquid. The roller I4 is of course like the roller smooth surfaced, and dries very quickly.

The principal advantage of my invention, however, lies in the fact that by the placing of the distributing tube 52 out of contact with the roller I! but within such proximity thereto that the liquid flows lengthwise along the tube between the openings therein and across the gap between the tube and the roller, 3, very uniform moistening of the roller H is accomplished without dipping the roller in liquid, and without a spraying mechanism or wick mechanism which would provide additional means for evaporating the liquid into the surrounding air.

Having thus described my invention, I claim: A moiste-ning device for moistening copy sheets in a duplicating machine of the type wherein a copy sheet moistened with an ink solvent is pressed against a master sheet having the copyable matter thereon in ink that may be dissolved by said solvent, said moistening device comprising roller means to spread the solvent on a copy sheet, a source of liquid supply, a tube, and a roller forming part of said roller means, extending lengthwise of and parallel to said tube and spaced therefrom, the tube having openings therein on the side facing the roller, the openings being spaced apart lengthwise of the tube and said tube and roller being in such close proximity that the liquid bridges the gap between them in preference to flowing to the under side of the tube, said tube having a restricted inlet of substantially less capacity than the openings in the tube whereby to prevent building up liquid pressure in the tube.

HENRY P. KEIL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,218,112 Kaufmann Oct. 15, 1940 2,247,134 Roethe June 24, 1941 2,264,578 Marchev Dec. 2, 1941 2,257,982 Kokay Dec. 30, 1941 2,277,960 Denison Mar. 31, 1942 2,296,472 Kokay Sept. 27, 1942 2,299,967 Denison Oct. 27, 1942 2,492,377 Camphouse Dec. 27, 1949 

